This is a multidisciplinary program involving biochemistry, cell biology, medicine and pathology that is oriented toward lung cell biology and lung biochemistry. The focal points are the interstitium of the lung parenchyma, surfactant,and the smooth muscle and extracellular matrix of pulmonary blood vessels. The theme of the project is that extracellular matrix has a vital role in normal lung development and maintenance of normal lung structure and that disturbances in synthesis, turnover and distribution of matrix are central to diseases of lung structure such as pulmonary emphysema, idiopathic pulmonary fibrosis and various forms of chronic pulmonary hypertension. The program will address expression of lung fibroblast phenotype, regulation of production of extracellular matrix, mechanisms and consequences of turnover of lung extracellular matrix, and the biochemistry of protein associated with surfactant. The following molecules will be emphasized: fibronectin, the fibronectin receptor, surfactant- associated collagenous proteins, elastin, human neutrophil elastase, type IV collagen, human interstitial collagenase, human tissue inhibitor of metalloproteinases (TIMP) and a newly discovered elastogenic factor released by pulmonary artery smooth muscle cells. Experimental models will be used to examine the role of matrix molecules in lung development, mechanisms of fibroblast migration into plasma clot, the effects of human interstitial collagenase upon lung, the effects upon inflammatory cells of peptides released from lung basement membrane, alterations in pulmonary artery matrix in pulmonary hypertension induced by alveolar hypoxia, and the regulation of collagenase production by inflammatory cells and isolated structure cells of the lung. Human studies will utilize lung biopsy material, cells and fluid obtained by bronchoalveolar lavage, plasma and circulating inflammatory cells. The investigative approaches will include cell culture, a variety of protein chemistry techniques, immunoassys, immunolocalization at the light and EM levels, determination of mRNA levels by quantitative assay and by 'in sit' hybridization, and radiocarbon dating to determine rates of human lung elastin turnover. Core facilities will be develop polyclonal and monoclonal antibodies assist with immunological procedures, will be used to develop polyclonal and monoclonal antibodies, assist with immunological procedures, and perform histological analyses that will utilize immunological reagents and molecular probes.